package extract

import (
	"bufio"
	"fmt"
	"os"
	"path/filepath"

	log "github.com/sirupsen/logrus"
)

const (
	AOSFrameLength    = 1024
	AOSTempDataPrefix = "AOS_Data_"
)

var AOSSyncWord = []byte{0x1A, 0xCF, 0xFC, 0x1D}

type AOSFrame struct {
}

func (p *Extractor) ExtractAosData() error {
	// 打开传输帧文件 - 一次读入内存
	rawData, err := os.ReadFile(p.params.InputData)
	if err != nil {
		log.Println("read data from", p.params.InputData, "error:", err.Error())
		return err
	}

	name := filepath.Base(p.params.InputData)
	aosDataFile := filepath.Join(p.params.TempPath, AOSTempDataPrefix+name)
	foData, err := os.OpenFile(aosDataFile,
		os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0777)
	if err != nil {
		fmt.Println("create data err", err.Error())
		return err
	}
	defer foData.Close()
	wData := bufio.NewWriter(foData)

	var validFrameCnt int
	var errFrameCnt int

	for i := 0; i < len(rawData); {
		// 寻找帧头 0x1A CF FC 1D
		if i+4 > len(rawData) {
			log.Info("end of raw data")
			break
		}

		if rawData[i] == 0x1A && rawData[i+1] == 0xCF && rawData[i+2] == 0xFC && rawData[i+3] == 0x1D {
			// 找到帧头
			log.Debug("detect AOS frame")
		} else {
			i++
			continue
		}

		if i+1024 > len(rawData) {
			log.Info("not enough data for AOS frame")
			break
		}

		// 读取完整帧
		if LDPCCheck(rawData[i:i+1024]) != nil {
			errFrameCnt++
		}

		wData.Write(rawData[i+10 : i+894])
		i += 1024
		validFrameCnt++
	}

	log.Println("valid AOS frame cnt:", validFrameCnt)
	log.Println("error AOS frame cnt:", errFrameCnt)

	return nil
}

func LDPCCheck(frame []byte) error {
	return nil
}